The silylated urethane resins disclosed in U.S. Pat. Nos. 3,030,020 and 3,350,011, which are favorably adhesive to a wide variety of materials and environmentally friendly, are resins meeting the demands of the times and thus, resins of practical use in general adhesion applications. However, the silylated urethane resins are more viscous because of the urethane bonds contained therein, resulting in restriction on blending ratio of components for various adhesives and sealants. Further, the modified silicone resins having a polyoxyalkylene polymer as the main chain skeleton disclosed in Japanese Patent Application Laid-Open (JP-A) No. 08-337713 and others are less viscous, but not sufficiently adhesive because the resins do not have active hydrogen atoms in the molecular skeleton, and thus there exists a need for improvement in adhesiveness.
Further, silylated urethane resins having a (meth)acrylic ester polymer or a hydrocarbon polymer as the main chain skeleton are also known, but they are highly viscous, causing a problem in processability.
Furthermore, a curable epoxy compound containing hydroxyl groups and a thioether group in the molecule which is a reaction product from a hydrolysable silyl group-containing mercaptosilane and an epoxy compound, was described in JP-A No. 06-293784, but the curable epoxy compound is also highly viscous, causing the problem in processability.
An object of the present invention is to provide a curable resin having a silyl group at the terminal that is also moisture-hardening resin lower in viscosity and superior in adhesiveness, a production method thereof, and a composition containing the same as a component.
After intensive studies, the inventors have found that the object of the invention could be achieved by a resin prepared by an active hydrogen in the molecule of a polymer having an polyoxyalkylene, (meth)acrylic ester, or hydrocarbon as the main chain skeleton and an allyl group at the terminal by modification, and additionally introducing a hydrolysable alkoxysilyl group, not via a urethane bond, at the terminal thereof, and completed the invention.